PORT ST. LUCIE ­— The moment Johan Santana delivers his first pitch today, Mets spring training will have a completely different feel from 2011.

A year ago, Santana was recovering from surgery to repair a torn anterior capsule in his left shoulder, and the best-case scenario was the lefty would return in June. The Mets instead got the worst-case scenario, which meant Santana missed the entire season.

He now is set to take the mound against the Cardinals at Digital Domain Park, marking his first appearance against major league hitters since Sept. 2, 2010, when he left a game against the Braves at Turner Field with what the Mets originally termed a strained pectoral muscle.

Less than two weeks later, he was on the operating table for shoulder surgery.

Santana joked with reporters yesterday, but did not want to discuss today’s start. But it’s a safe guess he has a few jitters, given he admitted to being nervous last week before he faced his teammates in batting practice.

“The only guy that is probably more excited than me is Johan,” Terry Collins said. “I’m real excited to see him out there, and obviously two days after [today] is when I want to really see how he’s doing, because that will be a test on how he’s going to bounce back.”

Santana will throw 40 pitches or two innings, whichever comes first. If all goes well, he would stretch out for a longer outing Sunday against the Marlins.

“It’s to the point where it’s going to be exciting, but he’s also getting ready, he’s got to get himself ready for the season, too,” catcher Josh Thole said. “It’s not necessarily a rehab program. He’s going to come in and throw two innings just like the other starters.”

Thole said Santana’s velocity is still progressing, but his control isn’t an issue.

“The command of his offspeed pitches is what I think takes the cake,” Thole said. “It’s watching him throw the changeup pretty much at will where he wants, using the slider, front door, back door, however else he wants to use it.

“That to me is what definitely makes him stand out even after big arm surgery. You wonder if they’re going to have that, and he came out — it’s like riding a bike for him.”

Though today’s appearance will be another step forward for Santana, Collins does not want his ace getting too fired up. The manager already has spoken to Santana about that issue.

“I said to him the other day, ‘All I want you to do is approach this like you’ve been approaching your [side throwing sessions],’ ” Collins said. “He’s going to have the adrenaline flowing and we’ve got to realize that, and I certainly will, but he’s smart enough to know it’s all a process.

“He’s pitched enough spring training games to understand what it means, and I just know he wants to come out of this healthy, as we all do.”

Thole said Santana has made his presence felt this spring.

“He walks in and everybody starts poking fun and joking around with each other,” Thole said. “That’s what Johan brings. Because he can do that, you know he’s feeling good.”